1. Field of Invention
This invention relates to a merchandise push-out device for a vending machine, which pushes forward the lowermost piece of merchandise in a merchandise stocker in which merchandise is stacked vertically and supports the remaining pieces of stacked merchandise in a substantially horizontal position. This device is directed to a merchandise push-out device for vending machines used to sell box-shaped merchandise such as cigarettes. It is especially useful for energy-saving vending machines which utilize batteries as their power source.
2. Description of the Prior Art
Vending machines powered by batteries have attracted attention lately due to their advantage of being able to eliminate restrictions regarding the location of the machines. Due to the limitation of available electricity, these types of battery-operated vending machines must be designed so that their internal mechanism operate with as little power consumption as possible.
In such a vending machine, one of the typical internal mechanisms operated by electricity is a merchandise push-out mechanism. This type of merchandise push-out mechanism depends, for example, on the merchandise stock method. When the merchandise is stacked vertically and the lowermost piece of merchandise is pushed forward, prompting the next piece of merchandise to move downward due to its own weight, the following mechanism may be adopted. A motor-driven arm, whose top part rocks back and forth from the rocking shaft, is installed with a push-out member being installed at the top end of the arm. By rocking the arm, the lowermost piece of merchandise may be pushed forward from its back by the push-out member. This mechanism has a special advantage of being effective in reducing the thickness of the vending machine.
There are, however, the following problems concerning the above-mentioned rocking arm push-out mechanism in the previous proposal. As shown in FIG. 4, when the push-out member 100 moves forward from the retreat position and pushes the lowermost piece of merchandise A inside the stocker 101, the upper pieces of merchandise above the push-out member, as shown in FIG. 5, tilt. This causes the other merchandise A in the upper part of the stocker to also tilt. Therefore, as shown in FIG. 6, when the push-out member retreats after pushing out the lowermost piece of merchandise A, the push-out member must retreat while pushing up the above-mentioned tilted merchandise A. During this process, the merchandise is tilted in the opposite direction, and when the push-out member moves out from under it, the remaining merchandise falls horizontally onto the support guide plate due to the combined weight of the remaining merchandise.
Such see-saw movement of the merchandise creates friction between the pieces of merchandise inside the stocker. This increases the possibility of the merchandise being damaged. Furthermore, this movement applies a large load to the drive motor, which activates the push-out member, since the push-out member is required to push up all of the stocked merchandise while retreating. In other words, the motor load includes the load caused by the force pushing up the stock merchandise, as well as the load caused by the force pushing out the lowermost piece of merchandise. Consequently, in addition to the power consumed purely for pushing out the merchandise, the power for pushing up the total stocked merchandise is consumed wastefully.